Polyhydroxy fatty acid amide surfactant is a desirable component of detergent compositions for its cleaning and mildness characteristics, but it can be difficult to handle in the plant and to formulate into a composition because of its high melting point. The melting point of a 50% N-cocacyl N-methyl glucamide mixture, for example, is about 142.degree. F. (61.1.degree. C.). It is difficult to pump concentrated polyhydroxy fatty acid amide unless it is diluted or heated to a temperature at or above its melting point. Polyhydroxy fatty acid amide is also often difficult to formulate into detergent compositions. For example, it may resolidify upon introduction to the cooler liquid ingredients. To get this component into solution often requires a great deal of stirring, heating above the melting point, diluting and/or use of solvents.
It has been found that a pumpable polyhydroxy fatty acid amide composition can be formed by mixing certain soluble inorganic salts or C.sub.1-3 carboxylate salts into heated polyhydroxy fatty acid amide surfactant. Surprisingly, sodium and ammonium salts do not yield this benefit. The polyhydroxy fatty acid amide composition is thus easier to handle in the plant and to formulate into detergent compositions, particularly liquid detergent compositions.
The use of N-alkyl glucamides in detergent compositions has been discussed. U.S. Pat. No. 2,965,576, issued Dec. 20, 1960 to E. R. Wilson, and G.B. Patent 809,060, published Feb. 18, 1959, relate to detergent compositions containing anionic surfactants and certain amide surfactants, which can include N-methyl glucamide, added as a low temperature suds enhancing agent.
U.S. Pat. No. 2,703,798, issued Mar. 8, 1955 to A. M. Schwartz, relates to aqueous detergent compositions containing the condensation reaction product of N-alkyl glucamine and an aliphatic ester of a fatty acid. It is also known to prepare a sulfuric ester of acylated glucamine as disclosed in U.S. Pat. No. 2,717,894, issued Sep. 13, 1955, to A. M. Schwartz.
European Patent 0 285 768, published Oct. 12, 1988 to H. Kelkenberg et al relates to the use of N-polyhydroxy alkyl fatty acid amides as thickening agents in aqueous detergent systems. Included are amides of the formula R.sub.1 C(O)N(X)R.sub.2 wherein R.sub.1 is a C.sub.1 -C.sub.17 (preferably C.sub.7 -C.sub.17) alkyl, R.sub.2 is hydrogen, a C.sub.1 -C.sub.18 (preferably C.sub.1 -C.sub.6) alkyl, or an alkylene oxide, and X is a polyhydroxy alkyl having four to seven carbon atoms, e.g., N-methyl, coconut fatty acid glucamide.